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SYSTEM DESCRIPTION, INSTALLATION, AND MAINTENANCE MANUAL
MCS--4200/7200 Multi--Channel SATCOM System
(b) Data Entry
1
When the user types the appropriate characters using the SCDU keypad,
the characters are echoed on the scratchpad. After data entry, the user must
push the appropriate LS key adjacent to the data field where the data is to
be displayed. The SDU then checks the data for format and acceptability
(out-of-range, entry not permitted into the field, etc). If the data is incorrect,
the SDU leaves the previous data in the field and displays the appropriate
error message in the scratchpad. If any LS key is pushed adjacent to a
blank or nonselectable field, the scratchpad message 1 (i.e., NOT
ALLOWED) is issued. If the entry was rejected because an incorrect LS key
was pushed, the entry is accepted if the correct LS key is subsequently
pushed.
(c) Scratchpad Message
1
If the SDU determines a data entry does not conform to format or
acceptability requirements after an entry is attempted, the SDU issues a
scratchpad message prompting the user for the correct data. The user can
clear a scratchpad message by using the clear (CLR) key, or by entering
data into the scratchpad over the message.
(d) CLR and DEL Keys
1
General
a
The CLR and delete (DEL) keys are used to clear the scratchpad and
alter the data fields. Generally, for MCDUs that have only a CLR key
(e.g., Airbus and Douglas) the scratchpad is cleared and the data fields
are altered by using this key. For MCDUs that have both CLR and DEL
keys (e.g., Boeing), the scratchpad is cleared using the CLR key, while
the data fields are altered using the DEL key.
2
CLR Key
a
Pushing the CLR key clears the scratchpad message. When the
scratchpad contains user-entered characters, momentary actuation of
the CLR key clears the last entered character, while continual actuation
of the CLR key clears the entire contents of the scratchpad.
b
When the scratchpad is empty, pushing the CLR key causes CLR to be
displayed in the scratchpad indented five spaces. If an LS key is pushed
and the field adjacent to the LS key is specified to be either erasable
(e.g., an unprotected number) or a default maintained value (e.g.,
protected number priorities), the field is cleared or reverts back to its
default value, as applicable.
c
For compatibility with the Boeing 777 AIMS/CDU, the SDU clears the
entire scratchpad when the CLR command is received with the repeat
bit set.
Honeywell International Inc. Do not copy without express permission of Honeywell.
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15 Jul 2006
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